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000
FXUS66 KOTX 211647
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
947 AM PDT Tue May 21 2013

.SYNOPSIS...
The mild spring weather will come to an end. A strong cold
front will sweep through the region today and this evening with
showers...a chance of thunderstorms and breezy winds. Cool and
showery weather will continue through much of the week, but will
improvement a bit for the holiday weekend.

&&

.DISCUSSION...
Updated the forecast to keep up on the quickly changing pattern
today. A deep upper level low is rotating to the WA coast while a
strong cold front has slipped east of the Cascades and roughly
extends from Chelan to Hanford. Radar shows a dense line of
showers along and ahead of the front. Embedded thunderstorms were
reported early this morning which coupled with the mid level
instability, but the lightning strikes have waned in the last
hour. Local heavy downpours accompanied the thunderstorms and
Wenatchee saw 0.14" in less than an hour. The front will slowly
sweep east and take on a negative tilt through the day. Not
expected much temperature rises today in the Cascades behind the
front. Meanwhile, the Idaho panhandle and extreme eastern WA will
warm up into the lower 70s with rising dewpoints. Instability will
be on the rise this afternoon in this area with Capes reaching
500-700 j/kg. This coupled with increased 0-6km speed shear and
low level directional shear ahead of the front, has the potential
for strong thunderstorms will some organization. The cons for
strong thunderstorm development will be the increase of mid and
high clouds which may cap the activity. Will continue to monitor.
/rfox.

&&

.AVIATION...
12Z TAFS: A cold front moves from the Cascades to Idaho trough
the next 12-18 hours, while the center of an upper low swings in
from the west/southwest tonight into Wednesday morning. The front
will bring an increasing area of rain near the western TAF sites
this morning and early afternoon. Scattered showers will develop
further east this afternoon, while a steadier band of
precipitation is expected to come by late afternoon and evening
with the cold front. A chance of thunderstorms also exists
throughout much of the region, with the best chance for organized
activity north and east of KGEG. Storms may be locally strong with
gusty winds/small hail. Tonight the incoming upper low is expected
to keep precipitation chances high across eastern TAF sites. Local
MVFR cigs are possible in the more persistent precipitation. Colder
air accompanying the upper low will allow some snow to mix in
toward Wednesday morning but surface temperatures are expected to
limit the accumulation threat below 3000 feet. /J. Cote`



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        70  41  51  36  61  42 /  30  90  90  40  30  30
Coeur d`Alene  72  41  48  36  59  41 /  30  90  90  50  40  40
Pullman        70  38  51  35  60  41 /  20  80  80  30  40  40
Lewiston       78  44  59  41  66  46 /  40  60  70  30  30  40
Colville       74  45  55  37  66  41 /  50  90  90  60  50  40
Sandpoint      73  43  50  36  59  39 /  30  90  90  80  40  50
Kellogg        75  40  44  34  55  40 /  30  90  90  70  50  50
Moses Lake     69  43  62  40  68  44 /  70  50  30  30  30  30
Wenatchee      63  43  58  42  65  45 /  70  60  40  40  50  30
Omak           66  43  59  38  66  41 /  80  80  70  50  50  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$